FROGLOG
IUCN/SSC Declining Amphibian Populations Task Force December 1995 No 15
Update on the NAAMP The North American Amphibian Monitoring Program is being created to: 'provide a statistically defensible program to monitor the distributions and relative abundance of amphibians in North America, with applicability at the state, provincial, ecoregional and continental scales.' To that end, meetings were held in Indiana Dunes National Seashore in September 1994 where these goals were developed and determined to be feasible. A collaborative research program was initiated for the following summer. The results of these investigations were presented in September 1995 at The Canada Centre for Inland Waters in Burlington, Ontario. These meetings, research and email discussions have spawned the working drafts on Calling Surveys, Larval Surveys, Terrestrial Salamanders, Herp Atlases and Western North America. Associated with these sections are two appendices. Appendix 1 is a treatise on statistical sampling and sampling frames. This topic is given a thorough treatment, to strengthen current and future efforts. Appendix 2 will be a list of North America amphibians and some indication of the applicability of proposed monitoring techniques to tracking trends in their populations. These documents present the statistical and scientific evaluations of monitoring protocols. The next objective is the implementation of these recommendations. Of the four monitoring areas, calling amphibian
surveys is probably the closest to implementation. The other areas need additional research and pilot work before effective implementation can begin. The final comment period was extended to December 8th 1995. After comments are incorporated, these documents will be distributed and will be considered to embody the collective thoughts of North American amphibian biologists. Copies of the NAAMP will be available after January 1st, 1996, and can be obtained by contacting Sam Droege (NBS, 12100 Beech Forest Dr., Laurel, MD 20708, phone: 301497-5840, fax: 301-497-5784, email: frog@nbs.gov), or Web site: http://www.im.nbs.gov/amphib/naampi ntro.html Christine Bishop (Canadian Wildlife Service) & Mike Lannoo (U.S. Chair DAPTF).
Abiotic Disturbances in the Lesser Antilles The recent passing of Hurricanes Iris, Luis, and Marylin across the northern Lesser Antilles (hardest hit were Anguilla, Antigua & Barbuda, Dominica, and St. Martin) has received considerable attention in the popular media because of the potential economic impact on these small, tourism-dependent islands. These fierce storms sprang from an unusual abundance of climatic disturbances in the Atlantic. The threat of further storms continues. As members of a scientific team studying herpetological diversity on the island of Montserrat, with the assistance of the government, we observed alteration of the habitat caused by these hurricanes. However, the storms only supplemented the effects of recent volcanic activity.
The clearest result of storm activity is the transfer of dense vegetation and debris from the canopy to the forest floor. At our site on Mango Hill in northern Montserrat, the habitat initially allowed relatively easy access to streams and calling sites of both Eleutherodactylus johnstonei and Leptodactylus fallax. After Hurricane Luis, much of the protective foliage had either been removed entirely or had fallen to the ground. It is as yet unknown whether L. fallax, a large (SVL up to 200 mm) and economically important species, requires open ground to optimize foraging or behavioral interactions, but most wide openings have now received debris. Nevertheless, due to the heavy rainfall in conjunction with the hurricane, calling activity of both frog species was much increased during the immediate aftermath. Volcanic activity seems to have had a more obvious negative impact on L. fallax. Several large emissions of ash from Soufriere volcano in southeastern Montserrat have occurred, and much of the foliage in the vicinity of the volcano, primarily to the northwest of Chances Peak, was covered with an ash layer. The heavy rains during hurricane activity washed this ash onto the ground and into the ravines and waterways. A site supporting a high density of L. fallax juveniles prior to some major ash falls appears to have been inundated subsequently with ash-laden runoff, and we observed dead and dying juveniles in the shallow rock pools. Emissions of Soufriere volcano are high in sulfur, and a change in water pH is a possible reason for the unhealthy young frogs. A later visit to the same site revealed that many of the pools had become filled with a grey mud and neither juveniles nor adults were seen. It is unlikely that either volcanic or hurricane activity will lead to the extirpation of populations of frogs on Montserrat. However, a careful